In vehicle tyre manufacturing, an airless tyre is known, from Patent Application WO 2005/082643 filed by the Applicant, comprising an annular body of elastomeric material, in turn comprising a tread which rolls on the road surface, and a tread reinforcing strip made of elastomeric material and placed inwards of the tread. The reinforcing strip comprises a number of blocks which project inwards of the tyre, are arranged contacting one another to withstand circumferential compression on the tyre, taper inwards of the tyre, and are each connected to the adjacent block by a respective virtual hinge. When the tyre tread encounters an obstacle, i.e. a concentrated external load is applied, the virtual hinges oppose minimum resistance to flexing of the reinforcing strip inwards of the tyre, so the blocks around the obstacle rotate in opposite directions to form a number of V-shaped slits, the flare of which varies, depending on the distance from the obstacle, and is maximum at the obstacle itself.
Though widely used, known airless tyres of the above type perform poorly in the presence of obstacles. This is mainly due to the way the reinforcing strip is made, the circumferential action of which varies considerably and locally as the wheel is about to roll over the obstacle. As a result, the contact pressure between the various parts of the tread and the road surface is far from even and homogeneous, as required to achieve optimum grip and long life of the tyre.
Tests show that the contact pressure between the blocks falls at the obstacle, and increases sharply up- and downstream from the obstacle, in two substantially rectangular regions.